Hi Kyley
Yes, I do receive WM_USER
messages. This is how the DLL communicates. As I
mentioned, it works perfectly if I put all the message checking in
the mainform, but it doesn't work in the separate unit, even with
the AllocateHWnd.
Here is all my relevant
code.
TMyComponent =
class(TComponent)
private
FHandle:
HWnd;
procedure WndProc(var Message:
TMessage);
end;
constructor
TMyComponent.Create;
begin
inherited
Create(AOwner);
FHandle :=
AllocateHWnd(WndProc);
end;
destructor
TMyComponent.Destroy;
begin
DeallocateHWnd(FHandle);
inherited
Destroy;
end;
procedure
TMyComponent.WndProc(var Message: TMessage);
begin
with
Message do
if Msg = WM_USER
then
begin
Result
:= lparam + wparam //(for example)
end
else Result :=
DefWindowProc(FHandle, Msg, wParam, lParam);
end;
I get a couple messages when
the program loads but I never get Msg = WM_USER.
Do you see any problems with this
code?
The following code,
however, when placed in the mainform does detect WM_USER
messages.
TForm1 =
class(TForm)
...
procedure
WMUSER(var Message: TMessage); message WM_USER;
end;
procedure
TForm1.WMUSER(var Message: TMessage);
begin
with
Message do
if Msg = WM_USER then showmessage('It
Works!');
end;
I've tried different combinations of
the syntax, including the message
WM_USER; bit in the unit but it doesn't
make any difference at all. In fact I still get other messages
when the program starts.
Thanks for the help.
Ross.
-----
Original Message -----
Sent:
Monday, June 27, 2005 10:01 PM
Subject:
[Spam] Re: [DUG] Intercepting messages in separate units
Try the wrapper class just incase you have made a
blooper. but it is unlikely that you will ever receive a message
with the ID WM_USER. that is simply an offset to coordinate with
windows messages. eg WM_USERLOGON = WM_USER+1 is an example of a
user defined message.
then
myobject =
class(TObject)
procedure WMUSERLOGON(var
msg:TMessage);message WM_USERLOGON;
end;
the above
procedure will only ever receive that one message. You need to
know exactly what messages you are expecting from the
dll.
if you use my wrapper, and attached an instance of the
above object to message handler it will route the messages to that
instance..
Ross Levis wrote:
Thanks for that Kyley. I
managed to implement AllocateHWnd etc, and everything appears
correct and logical. It's picking up some Windows messages
but not the WM_USER messages being sent. WM_USER is
message number 1024. I'm getting Message.Msg = 28 and
that's about it.
I tried the same code in the
mainform as a test and this worked but only after I specified
the following:
procedure MyMessage(var Message:
TMessage); message WM_USER;
If I leave off "message WM_USER",
then nothing gets through to the procedure in the mainform at
all.
I tried this in the unit and it
doesn't make any difference. Message 28 is still getting
to the procedure and no 1024.
You can tell I'm no expert when it
comes to this. Do I need to use your fancy looking wrapper
class?
I must be missing
something.
Thanks,
Ross.
-----
Original Message -----
Sent:
Monday, June 27, 2005 7:13 PM
Subject:
[Spam] Re: [DUG] Intercepting messages in separate units
in the forms unit
function
AllocateHWnd(Method: TWndMethod): HWND; deprecated; {
moved to Classes.pas }
{$EXTERNALSYM
AllocateHWnd}
procedure DeallocateHWnd(Wnd:
HWND);
deprecated; { moved to Classes.pas }
read the
help will sort you out just fine
Ross Levis wrote:
I'm writing a component which
communicates with a 3rd party DLL using WM_USER
messages. After loading the DLL, I need to
tell the DLL the handle to send user messages back to,
so my unit can intercept them, but I don't know where to get
a handle from. I know how to do it in the mainform of
a program but not in a separate unit. The messages
sent to the mainform do not appear to reach my
unit.
What do I need to do to make
this happen?
Thanks,
Ross.
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_______________________________________________
Delphi mailing list
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http://ns3.123.co.nz/mailman/listinfo/delphi
_______________________________________________
Delphi mailing
list
[email protected]
http://ns3.123.co.nz/mailman/listinfo/delphi
_______________________________________________
Delphi mailing list
[email protected]
http://ns3.123.co.nz/mailman/listinfo/delphi
